A common treatment for a cataract involves removal of the diseased lens from a patient's eye followed by replacement with an Intraocular Lens (IOL). Originally, the entire lens and capsule were removed and replaced. More modernly, the lens is removed from the capsule, in situ, and the new IOL is inserted into the capsule.
In a typical cataract procedure, access to the lens is obtained and the lens is fragmented and/or emulsified. For example, the lens can be emulsified using a traditional ultrasonic handpiece (a process known as “phacoemulsification”), or, more modernly, the lens can be fragmented using a femtosecond laser. Once fragmented or emulsified, the lens material can be removed from the capsule, for example, by aspirating the material using an aspiration needle. Once the lens material has been removed, an IOL can be inserted into the remaining portion of the lens capsule.
To perform the procedures described above, an opening in the lens capsule is required. Two possibilities for this opening include an anterior capsulotomy in which an opening is made on the anterior surface of the lens capsule and a posterior capsulotomy in which an opening is made on the posterior surface of the lens capsule. Typically, for an anterior capsulotomy, the surgeon gains access to the capsule and lens through incisions that are made on the cornea or limbus. However, these incisions can adversely affect the refractive properties of the eye, including the inducement of undesirable astigmatism.
Another drawback associated with a typical anterior capsulotomy procedure involves anatomical considerations. In more detail, access to the anterior capsule surface necessarily involves transit through the relatively small anterior chamber of the eye. Unfortunately, there are a number of surgical problems associated with passing tools, such as the phacoemulsification probe and aspiration needle, through the small anterior chamber of the eye. Moreover, the anterior capsulotomy procedure can disturb other fragile anatomical structures that are anterior to the crystalline lens.
Unlike the anterior capsulotomy, access for a posterior capsulotomy can be obtained using incisions through the sclera on the side of the eye. These incisions do not, in general, affect the refractive properties of the eye like the incisions described above that are made on the cornea or limbus. In addition, there is more operating room on the posterior side of the crystalline lens than the small anterior chamber of the eye. And, in many instances, additional room for tool manipulation can be made on the posterior side of the crystalline lens by performing a partial vitrectomy.
Another advantage of a posterior capsulotomy is that the optical barrier (e.g. the anterior surface of the capsule) is maintained intact during a surgical procedure. Lastly, the use of a posterior capsulotomy can provide flexibility for combining the capsulotomy procedure with other surgical procedures in the back of the eye.
In light of the above, it is an object of the present invention to provide a system and method for performing a posterior capsulotomy.
Another object of the present invention is to provide a system and method for performing a posterior capsulotomy procedure to accommodate the insertion of an Intraocular Lens (IOL) into the lens capsule of an eye.
Still another object of the present invention is to provide a system and method for performing a posterior capsulotomy procedure using laser techniques which is simple to implement and is relatively cost effective.